Antigen peptide transporter 1 (TAP1) (TAP1)

Antigen peptide transporter 1 (TAP1) is a member of the ATP-binding cassette (ABC) transporter family and plays a pivotal role in the adaptive immune system [1]. It forms a functional heterodimer with TAP2, located in the membrane of the endoplasmic reticulum (ER), where it facilitates the transport of peptides from the cytosol into the ER lumen [2]. These peptides, typically generated by the proteasome, are subsequently loaded onto MHC class I molecules for presentation to CD8+ T cells [3]. Mutations in the TAP1 gene are associated with Bare Lymphocyte Syndrome type I, a rare primary immunodeficiency characterized by a lack of MHC class I expression and recurrent bacterial infections [1, 4]. In the context of oncology, TAP1 is frequently downregulated by tumor cells as a mechanism of immune evasion, leading to reduced visibility to the immune system [5]. Furthermore, several viruses, such as Herpes Simplex Virus, produce proteins like ICP47 that specifically inhibit TAP1 to prevent the presentation of viral antigens [3].

Other names

ABCB2APT1PSF1RING4TAP1*0101Transporter 1 ATP-binding cassette sub-family B memberATP-binding cassette sub-family B member 2

Inhibition of peptide transport into the endoplasmic reticulum by viral proteins; restoration of expression to enhance antigen presentation in cancer immunotherapy.